(19)
(11) EP 0 082 519 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
05.09.1984 Bulletin 1984/36

(43) Date of publication A2:
29.06.1983 Bulletin 1983/26

(21) Application number: 82111824

(22) Date of filing: 20.12.1982
(84) Designated Contracting States:
DE FR GB NL SE

(30) Priority: 21.12.1981 JP 20508881

(71) Applicant: KAWASAKI JUKOGYO KABUSHIKI KAISHA
 ()

(72) Inventors:
  • Yoshida, Toshio
     ()
  • Atsuta, Toshio
     ()

   


(54) Method and apparatus for producing welded joint parts of pipes


(57) Tensile residual stress in an annular welded joint part (2) joining the ends of unit pipes (1) is mechanically removed by applying repeated hammering strokes against the inner surface of the pipes over the entire joint part thereby to cause this part to undergo locally plastic deformation. The repeated hammering strokes, which have a peening effect, are applied by several automatically operating hammering devices (21) mounted radially on a rotary head (18) secured to and unitarily moving with a shaft (6) which is driveable in rotation about its axis and in translation in its axial direction.







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